Seam lock opener



C. H. GREBE SEAM LOCK OPENER Jan. 4, 1955 2 Sheets-$heet l Filed June 17, .1952

INVENTOR.

CONRAD H GREBE ATTORNEYS Jan. 4, 1955 c. H. GREBE 2,698,641-

SEAM LOCK OPENER Filed June 17, 1952 2 sheets-sheet z c E fulllumuu u 1. 72

' INVENToR.

CONRAD H. GREBEA ATTORNEYS United States Patent O SEAM LOCK OPENER Conrad H. Grabe, Portland, Oreg.

Application .lune 17, 1952, Serial No. 294,023

Claims. (Cl. 153-54) The present invention relates to a sheet metal working device and more particularly to a machine for opening the pocket of a seam lock on the edge of a sheet metal member.

One manner of joining together a pair of sheet metal members is to preform the abutting edges of the members so that they may be fitted together to form an interlocking seam, an example of which is the Pittsburgh lock-type seam. The preforming operations are necessarily carried out on flat pieces of the sheet metal and if such are used in the llat condition, no trouble is encountered. In forming curved pieces for use in duct elbows and the like, however, "the flat pieces with the preformed edges formed thereon are passed through roller type bending machines, which operation closes the pocket in the seam which must be reopened before the curved piece may be assembled with another sheet metal member. A highly successful type of pocket opening device is the machine shown and claimed in my Patent No. 2,334,497, issued November 10, 1943, which comprises essentially a pair of feed rolls between which the sheet metal member is clamped and supported as it is passed through the machine and a wedge element supported on the frame of the machine and adapted to he inserted in the pocket to wedge the folded wall portion of the lock outwardly into a predetermined spaced relation with respect to the standing edge portion of the pocket as the sheet metal member passes through the machine. An inherent result of the operation of this machine, however, is to cause a curved sheet metal member to hatten out thereby reducing the curvature thereof. Thus the sheet metal members must again be subjected to a ctnvin y operation which if done in a roller type bending machine will again close the pockets so that they must be reopened.

Accordingly, a principal object of the present invention is to provide a new and improved machine for opening the closed pocket of a preformed seam lock on the edge of a curved sheet metal member without disturbing the urvature of the sheet metal member.

More particularly, it is an object of the invention to provide, in a sheet metal seam lock opener comprising essentially a feeding means and a wedge element to open the lock pocket, means for guiding a curved sheet metal member as it passes through the machine whereby the sheet metal member will retain its initial curvature.

A further object of the invention is to provide a sheet metal seam lock opening machine which comprises relatively few parts of rugged design and which is simple to operate.

In accordance with the present invention, there is provided a machine including a frame having mounted thereon a plurality of feed rollers adapted to engage and move through the machine a sheet metal member having a folded seam lock on the edge thereof. Supported on the frame of the machine is a wedge element adapted to Wedge open the lock pocket as the sheet metal member is fed by the rolls through the machine. Disposed on each of the opposite sides of the machine are guide elements mounted so that they may be brought to bear on the con- Vex surface of a sheet metal member passing through the machine and form with the contacting surfaces of the feed rolls a feed path conforming to the initial curvature of the sheet metal member whereby the sheet metal member will be retained in said curvature as it passes through the machine and will not be flattened out by the seam opening operation.

Other objects and advantages of the invention will become apparent in the following specification taken in connection with the accompanying drawings wherein like numerals refer to like parts throughout while the features of novelty will be pointed out with greater particularity in the appended claims.

In the drawings,

Fig. l is a side elevation of the sheet metal seam lock opening machine constructed in accordance with the invention;

Fig. 2 is a fragmentary of the machine;

Fig. 3 is a fragmentary, of Fig. 1;

Fig. 4 is a sectional view along line 4 4 of Fig. 3 slrilowing certain details of the construction of the mac ine;

Fig. 5 is a sectional view along line 5 5 of Fig. 4;

Fig. 6 is a schematic View illustrating the functions of certain of the elements of the invention; and

iig. 7 is an enlarged schematic view of a closed seam loc Referring rst to Fig. 7, a typical seam lock is shown wherein 16 indicates the body of a sheet metal member formed with an offset, folded wall portion 17 extending normally substantially parallel to the standing edge portion 1 to form a pocket 19 therebetween. In this instance the seam is shown with the pocket 19 closed, the purpose of this machine being to open the pocket to form the aforesaid normal, parallel condition of the folded wall and standing edge portions.

The machine as shown in the drawings comprises a frame having two leg portions lt) and 11, which are loosely connected together at their upper ends by means of a screw bolt 12. The opening through the upper end of one of the frame legs for receiving the bolt 12 is slightly elongate in the transverse direction, as indicated at 13, so as to allow limited transverse movement between the frame legs l@ and 11. rfhe lower end of the leg 11 is provided with a cylindrical portion 15 which is adapted to be cooperatively received in a suitable supportinlg socket (not shown) provided in a work bench or the li 'e.

The lower or free ends of the legs 10 and 11 are provided with feed rolls 2@ and 21, respectively, which are journaled between corresponding pairs of inwardly extending bosses 22, 23 and 24, 25 formed integrally with the lower portions of the respective frame legs. The feed rolls Ztl and 2l are arranged axially parallel, extending in the direction of the frame legs 19 and 11. The roller 20 is an idler, while roller 21 is a driver, it being provided with a gear 26 intermediate its ends, which gear is of a diameter somewhat less than the opposite end portions which end portions are knurled in order to provide for suitable frictional engagement with the sheet metal piece to be fed thereby. The gear 26 is meshed with a right angularly arranged gear 27 attached to one end of a driving shaft 23. The driving shaft 2S is journaled with a hub portion 29 formed integrally with the lower end of the frame leg 1l while the outer end of the shaft 28 is provided with a Granit handle 31 by means of which rotation of the driving roll 2l may be effected.

By virtue of the loose connection between the upper ends of the frame legs, they may be moved laterally apart to permit the insertion of a sheet metal piece between the feed rolls 2li and 2l, with the Lipper searned edge of the sheet metal piece extending beyond the upper ends of the rolls and substantially at right angles with respect thereto. The frame legs 10 and 11 are further adapted to be shifted toward each other so as to bring the rolls 20 and 21 into clamping engagement with the opposite sides of the sheet metal piece therebetween. A rod 35 is rigidly secured at one end to one of the frame legs, such as 11, and extends at right angles between the two frame legs, and through a cooperating opening leg 10. The two legs lil and 1l are normally urged apart by means of a biasing compression spring 36 arranged about the rod 35 between the stop collar 37 and the adjacent inner surface of leg 1t). To effect movement of the frame legs toward each other against the force of the elevation of the opposite side sectional view along line 3 3 provided in the opposite biasing spring 36, there is provided a pair of cooperating camming discs 38 and 39 arranged about the rod 35 between the outer surface of the leg 1G and the stop nut 40 on the outer end of rod 35. Camming disc 38 is lixedly secured against rotation to the frame leg while disc 39 is provided with a handle 42 for effecting rotation thereof.

Means are provided for wedging open the pocket of the seam lock as the sheet metal member passes through the machine. In my Patent No. 2,334,407, two types of seam opening elements were illustrated and described, one of which comprised a pair of rotatable disc tools adapted to receive the standing edge of a sheet metal seam lock between them with one of the discs inserted into the pocket of the seam lock whereby the folded wall lock portion is wedged into predetermined spaced relation with the standing edge lock portion as the sheet metal member is passed through the machine. However, as stated in my patent, the rotary disc type tools are not adapted because of the width across their midsection for opening the lock pockets on sheet metal pieces having a short radius of curvature. Better adapted for such pieces are the blade type tool elements described in detail in my patent and herein shown at and 61.

Referring now more particularly to Fig. 1, the blade type seam opening elements 6%, 61 are releasably supported on the offset portion of shaft 62 journaled in supporting leg 11, a handle 63 being provided on the outer end of shaft 62 to effect lowering and raising of the wedge elements 69 and 61. Each of the opening elements 60, 61 is provided with a tapered tip 65, the standing edge portion 18 of a seam being engaged therebetween with one of the tips inserted in the pocket 19 as the sheet metal member is moved through the machine. The mounting arrangement of the wedge elements is described in detail in my patent, supra, and no more need be said of the precise mounting arrangement except to say that the upper portion of the wedging elements comprises a bifurcated member forming a slot in which is received the rod 35. A stop member 64 is adapted to cooperate with the handle 63 is provided on leg 11 to regulate the depth to which the tips 65 of the wedging elements may be lowered.

All of the foregoing descriptive matter relates to the seam opening machine as it is described in my patent, supra, and for further details thereof reference is made to said patent.

In accordance with the present invention, I have provided guide means cooperatively arranged with the sheet metal feeding means for retaining a curved sheet metal member in its initial curvature throughout the traverse thereof through the machine. More particularly, I provide guide means supported on the frame and disposed on opposite sides of the feeding rolls and cooperatively arranged therewith so as to retain the sheet metal member in its preformed curvature. are in the form of roller elements mounted on the frame and adapted to be brought to bear against the convex surface of the sheet metal member passing through the machine as shown schematically in Fig. 6 wherein a first guide roller is disposed on the rear side of the machine and a second roller 71 is disposed on the front side of the machine in axially parallel relationship with the feed rolls 20, 21 and forming therewith a curved path within which a sheet metal member 72 is retained as it passes through the machine, the arrows A, B indicating the direction of reaction of the sheet metal member 72 to the action of rolls 20, 21 thereon.

Referring now more particularly to Figs. 1 and 3, the first guide roller 70 is supported in a first supporting means comprising the vertically spaced-apart, T-shaped elements 74, 75 connected by the web 76 extending longitudinally of the base portion of the elements 74, 75. The shaft of the guide roller 70 is supported at its opposite ends between the supporting elements 74, 75 near one end of the head portions thereof, the other end of the head portions being pivotally mounted on opposite sides of the bosses 24, 2S on the shaft of the drive roll 21. The surfaces of the bosses are recessed to receive the head portions of the supporting elements 74, 75, the shoulder 77 of the recessed portion serving as a stop in the pivotal movement of the first supporting means 73. Means are provided for positively adjusting the position of the first supporting means including a screw member 82 threaded through the leg 11 and adapted to abut at Preferably the guide means one end against the web 76 and urge or pivot the first supporting means so as t-o move the first guide roller 70 against a sheet metal member passing through the machine and bend it to the desired curvature. A handle 83 is provided at the opposite end of the screw member 82. A coil spring 80 fastened at one end to the base of the T-shaped element 74 and at its other end to a spring supporting arm 81 extending from the stop 64 on the side of the leg 11 is provided to draw the first guide roller 70 to one side and out of the tangential path between the feed rolls 20, 21.

In most instances a metal sheet can be satisfactorily processed by a machine having a guide roller on the rear side of the machine as specifically described above. As will be observed, the feed rolls will constrict the sheet to the tangent path therebetween even though the guide roller imposes a stress upon the sheet, and the sheet will have little tendency to pivot about the feed roll contact line. However, in some instances it may be desirable to more positively restrain the pivotal movement of a sheet and, therefore, a guide roller may be provided on the feed side of the machine. Referring now more particularly to Figs. 2, 3, 4 and 5, a gauge means is provided on the front side of the machine against which the upper edge of a sheet metal member may be aligned to guide it in a straight path through the machine. The gauge means includes a generally horizontally disposed U-shaped member having a relatively straight base portion extending at right angles to the tangential plane of the feed rolls, the gauge be.ng supported by the downwardly depending leg 91 mounted in the boss 92 on leg 10, a setscrew 93 being provided in the boss for adjustment of the position of the gauge. Extending between the arms of the U and parallel to the base are a pair of bracing rods 94, 95. The base mem-ber 90 and the rod 94 parallel thereto form the guide and support means for the second guide roller 71. The second guide roller 71 is rotatably supported on a perpendicularly extending bolt having an enlarged head 101 at its lower end. The guide roller element 71 is cut away intermediate its ends to provide clearance for the gear member 27. Threaded on the bolt 100 above the roller element 71 is a collar 103 of greater diameter than the spacing between the gauge base portion 90 and the bracing rod 94, a rectangular block 104 being threaded on the bolt 1G() above the collar and drawn tightly thereagainst. The block 104 has a width just slightly less than the spacing between the gauge base 90 and the bracing rod 94 and is disposed therebetween. The collar 103 is drawn tightly against the under sides of the guage base 90 and bracing rod 94 by a wing nut 10S or other suitable nut threaded on the end of bolt 100 and bearing against a lock washer 166 extending over the base 90 and rod 94.

In operating the machine, the guide rollers 70 and 71 may be moved or set in position to form a path of the desired curvature prior to starting the sheet metal member therethrough. Preferably, however, the second guide roller 71 is first positioned in a desired location and the sheet metal member started through the machine, after which the first guide roller 70 is adjusted by means of the screw element 82 to bring the sheet metal member into the desired curvature. This procedure is preferred since it precludes the chance of the sheet metal member catching against the surface of the first guide roller 79 which may stop its movement whereby the knurled surface of the feed roll 21 would mar the surface of the member if it continued to turn. Obviously, only one of the guide rollers need ybe adjustable and both guide rollers may be permanently affixed in position if a large number of sheet metal members ofthe same radius of curvature are to be produced.

Having described a preferred embodiment of the invention, it should be apparent that the invention permits -of modificati-on in arrangement and detail. I claim as my invention all such modifications as come within the true spirit and scope of `the appended claims.

I claim:

1. In a machine for opening the pocket of a seam lock on the longitudinal edge of a longitudinally curved sheet metal member, the combination comprising a frame, a pair of feed rolls mounted on said frame for feeding said sheet metal member longitudinally through said machine, means on said frame for wedging the folded wall lock portion into predetermined spaced relation with the standing edge lock portion as said sheet metal member is passed through said machine, and a pair of guide elements adjustably mounted on said frame, one on each offtheopposite sides of said machine, a support member for one of said guide elements pivotally mounted on the axis of one of said feed rolls, said guide elements being adapted to engage the convex surface of said sheet metal member and retain said sheet metal member in its initial curvature as it passes through said machine, and means for maintaining said guide elements in work-guiding position.

2. In a machine for opening the pocket of a seam lock on the longitudinal edge of a longitudinally curved sheet metal member, the combination comprising a frame, a pair of feed rolls mounted on said frame for feeding said sheet metal member longitudinally through said machine, means on said frame for wedging the folded wall lock portion into predetermined spaced relation with the standing edge lock portion as said sheet metal member is passed through said machine, and a pair of sheet metal member guide elements mounted on said frame, one on each of the opposite sides of said machine, one of said guide elements being mounted for pivotal movement about the axis of one of said feed rolls, the other of said elements being mounted for adjustment in -a direction parallel with a plane parallel with and intersecting the axes of said feed rolls, whereby said guide elements may be positioned to engage the convex surface of said sheet metal member to retain said sheet metal member in its initial curvature as it passes through said machine, and means cooperatively arranged with said guide elements to retain the same in work-guiding position.

3. A device for opening a lock seam on the longitudinal edge of a longitudinal curved sheet metal member, said device comprising a frame, a pair of -axially parallel feed rolls mounted on said frame and adapted to engage the opposite sides of a sheet -metal member inserted therebetween, a wedging member adj'ustably secured to said frame and adapted -to be inserted into the pocket of said lock seam as said sheet metal member is fed -between said feed rolls, a first guide roller, rst supporting means pivotally mounted on said frame for supporting said first guide roller in an axially parallel, spaced relation with respect to said feed rolls on one side of said machine, adjusting means operatively connected between said frame and said first supporting means for adjusting the position of said first guide roller means, said adjusting means including a screw element operable on advancement thereof Ato pivot said first guide roller into pressurable engagement with the convex surface of said member :and resilient means reacting against the movement of said screw element to withdraw said iirst guide roller as said screw element is retracted, a second guide roller means, and means mounted on said frame for adjustably supporting said second guide roller means in an axially parallel, spaced relation with respect to said feed rolls on the opposite side of said machine, said first and second guide roller means being adapted to engage the convex surface of said sheet metal member and define with the area of contact of said feed rolls a curved feed path conforming to the curvature of said sheet metal member whereby said sheet metal member retains its o riginal curvature during the lock seam opening operation.

4. In a machine for opening the seam lock on the edge of a Curved sheet metal member and comprising a frame, a pair of feed rolls on said frame for feeding said sheet metal member through said machine wi-th the seam edge thereof extending at right angles with respect to the axes of said feed rolls, and means mounted on said frame for extending into the lock pocket for opening said lock pocket as said sheet metal member is fed Ithrough the machine by said feed rolls, the combination therewith of a rst guide roller, support means on said frame for supporting said first guide roller on one side of said machine in :axially parallel relation wit-h said feed rolls, said support means lbeing swingable about the axis of one of said feed rolls, adjustment means operatively c011- nected to said support means for adjusting the position of said iirst guide roller, said adjustment means including a screw element mounted on said frame and operable to swing said first guide roller into pressurable engagement with lthe convex surface of said sheet metal member, a second guide roller and means on said frame operatively connected to said second guide roller for mounting said second guide roller in axially parallel, spaced relation with said feed rolls on the other side of said machine, said second guide roller being adapted engage said convex surface of said sheet metal memer.

5. In a seam lock opening machine including a pair of parallel feed rolls for feeding a curved metal sheet member through said machine, a guide roller for retaining said member in a predetermined path, a support member for -said guide roller including a pair of supporting rods extending at right angles to the axes of said feed rolls and parallel to the plane through said axes, a bolt adjustably mounted between said rods for movement longitudinally lthereof and extending therefrom parallel to said axes, said guide roller being rotatably mounted upon said bolt, and means cooperatively arranged between said bolt and said rod to maintain said Ibolt in adjusted position while permitting rotation of said guide roller.

References Cited in the tile of this patent UNITED STATES PATENTS 648,156 Stewart Apr. 24, 1900 1,767,755 Grotnes June 24, 1930 2,016,735 Abramson et al. Oct. 8, 1935 2,146,659 Stewart Feb. 7, 1939 2,334,407 Grebe Nov. 16, 1943 FOREIGN PATENTS 80,697 Austria May 10, 1920 

